title: Gadolinium-infusion magnetic resonance angiogram: a new, noninvasive, and accurate method of preoperative localization of impalpable undescended testes.
abstract: OBJECTIVE
  This study investigates the usefulness of Gadolinium (Gd)-infusion magnetic resonance angiogram (MRA) in the detection of impalpable undescended testes.
  
  
  METHODS
  Magnetic resonance (MRI) examination was performed in 14 patients with 17 impalpable undescended testes (unilateral, n = 11; bilateral, n = 3). MRAwasthen performed as follows: Gadolinium-DTPA-BMA (Omniscan) at 0.3 mmol/kg body weight was injected intravenously, and dynamic coronal examination using fast spoiled gradient recalled sequences was obtained with images taken at early arterial and delay venous phases. The testis was located by detection of the enhanced pampiniform venous plexus.
  
  
  RESULTS
  Of the 17 undescended testes, 11 canalicular hypoplastic testes and 3 intraabdominal testes were detected in both routine MRI and MRA. Three atrophic testes were found in the scrotum by MRA but not detected by routine MRI. The detection rates of impalpable testes by MRI and MRA were 82.4% and 100%, respectively. All imaging findings were confirmed by surgical exploration. There was no morbidity associated with MRA.
  
  
  CONCLUSIONS
  Gd-infusion MRA is an accurate and sensitive method of preoperative localization of impalpable testes and is superior to conventional MRI in the detection of atrophic testes.
authors.affiliation: Department of Diagnostic Radiology, Queen Mary Hospital, University of Hong Kong.
authors.forename: W W
authors.initials: WW
authors.lastname: Lam
authors.forename: P K
authors.initials: PK
authors.lastname: Tam
authors.forename: V H
authors.initials: VH
authors.lastname: Ai
authors.forename: K L
authors.initials: KL
authors.lastname: Chan
authors.forename: W
authors.initials: W
authors.lastname: Cheng
authors.forename: F L
authors.initials: FL
authors.lastname: Chan
authors.forename: L
authors.initials: L
authors.lastname: Leong
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D003456:Cryptorchidism / Q000175:diagnosis* / Q000601:surgery; D019786:Gadolinium DTPA; D006801:Humans; D007223:Infant; D007275:Injections, Intravenous; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008279:Magnetic Resonance Imaging; D008297:Male; D011300:Preoperative Care; D012680:Sensitivity and Specificity; D013737:Testis / Q000473:pathology
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA